Adjustable backing-off spear



l March 24,-- 1925.

M. s.. DICK ADJUSTABLE BAGKING OFF SPER` Fld Nov. 10, 1923 A A APatented Mar. 24, 1925. j

UNITED STATES PATENT oFF-ICE.

MILTON s. Dromer WHITTIER, CALIFORNIA., AssIGNoR or ONE-HALF To W. J.WELL- i MAN, or Los ANGELES, CALIFORNIA. Y Y

ADJnsTABLE BACKING-orr srnna.

Appiication mea November 1o, 1923. serial No. 673,967.Y

To all whom t may concern.'

Be it known that I, MILTON S. DICK, aV

citizen ,of the United States, residing vat Whittier, in the county ofLos Angeles and State of California, have invented a new and VusefulAdjustable Backing-Off Spear7 particularly to a device forl holding acasing collar so that an upper' joint of casing may be unscrewed fromVthecasing string. Y

In thedrilling of oilwells, it is necessary at frequent intervals toreduce the diameter `of the hole as` the4 depth thereof increases. Thehole is drilled as far as practical with a large diameter bitv and largediameter casing set. The lsize of the hole is thenrreduced and a stringof casing ofjvcorresponding size placedtherein, this casing extends thefull depth of the holef The small diameter casing isallowed to extend tothe top of the Well and after placement, is cemented o at the lower` endof the large diameter hole in which large casing has been previouslyplaced. After the smallvcasing `has been cemented in, it is frequentlyneces-- sary to cut olf the upper end of the casing to bring it down tothe proper level for receiving the casing head. This cuttingo may beaccomplished most satisfactorily by unscrewing the upper length ofcasing and cutting and threading same, whereupon yit is again screwedinto the top of thestring of casingand is then ready to receive thecasing head.

It is found that in an attempt to iunscrewthe upper joint of casing, therota-4 tion applied at the upper end will often cause the unscrewing ofa joint a considen' able distance down yfrom the top.y

It is the obj ect of my inventionr to provide a spear for' gripping thecollar atwhich the length of casing is toloe unscrewed, so that l .thiscasing may be unscrewed without dan-fVV ger of breaking a joint at alower level.

The invention provides an expansible `member having teeth on the outerfaces thereof so that when the member is eX- panded, these teethwillembed inthe pref viously placed casing and the collar, thus securingthe collar against rotation.

The especialadvantagesand further objects of the invention will be madeevident hereinafter.

Referring to the drawing, which is for illustrative purposes. only:

Fig. 1 is a fragmentary View showing the use of the backing off Ispear.Y

Fig. 2isan enlarged 'sectional view of the backing off spear incollapsed disposal. Fig 3 is a section taken on a plane represented bythe lineB- of Fig. 2. i Q InI Fig. 1 ofV the drawing, 11 represents a.large diameter casing` which has Vbeen previously set in the vwell. Inthis casing, a smaller casing'12 hasbeen placed and cemented in thecustomary manner. VBetween thedownwardly extending portion 13 of thecasing andthe upper length off casing 14 which it is desired to unscrew,is a collarV 15. The casing spear 17 is shown in eX- panded positionbetween the wall of the'casing 11 of the collar 15, in which positionthe collar 15 is securely gripped so that it cannot A,rotate whentorsion is applied to' the length 14:. As shown in Figs. 2 and 3, theexpansible member constituting the casing spear is comprised' of aprimary wedge mem-y ber 20 and a secondary wedgem'ember 21.

VThe outer face 22 of the lprimary -wedge'is of `convex form and isprovided with 'lo-ngitu'dinal teeth 23. The second wedgemember 21 hasthe face 24 thereof formed concave and is provided with teeth 25. Thecooperating `inclined faces' 27 of the .wedge Y members are machined andthe sidewalls 28 ofthe primary member 20. are channeled` out asindicated at 29v to receive the edges of side plates 32.

The side walls 33 of the secondary member` 21 are channeled as indicatedat 34: to

, receive the opposite edges -of the plates32 `which have inwardlyextending flanges 35 thereof arranged to inter-loclrwith the niember 21in the mannershown; Y 1

Machine screws 38 are provided which screw through the walls 28, thuscombining the side plate with the primary wedge 2O and causing them tomove along the channels 34 lof the secondary memberk 21 when a relativemovement is provided between the wedge members.

In order tok cause a lrelative expansion of Cil the spear, a relativemovement between the wedge members 2O and 21 is provided in thedirections indicated by the arrows 42 and43. *Thisy .movement isaccomplished means of a screw 44, the lower end 45 of which extendsthrough an opening in the bottom wall 46 of the secondary wedge member21 and is secured against longitudinal movement by collars 47 and48.Adjacent to the end wall 50 of the primary wedge member 20 is adivisionwall 5,1Which is spaced away from the wall 50 a distancesufiicient to provide space for a nutothrough xwhich the threadedportion 56 of. thescrew 44 extends. By rotating the screw 44, it 1scaused to advance through the mit 5,5, thns accomplishing a relativemovementbetween thewedge members 2 0 21. The v,spear is generallysuspended from a small diameter pipe 60, Fig. '1, whichmayvbeconveniently secured to the upper end 61k of the screw 44 -by theuse of a pin 6,2.

The spear is lowered between the outer casing 11 and the inner easing 121n eollapsed positionl asshown in Fig. 2, where-` upon the pipe is4rotated and the wedges 20 and 21 expandedso'as to embed the teeth 23and 125 respectivelyin the walls the casing 11 and the collar 1 5. rllheupper length of casing 14 may then Avbeunscrewed from rthe collar 15,cutto 'the proper-length, and threaded to receive the casing head. Theteeth 23 and 25 are in the drawing pitched to resist lett handrotationotthe collar 1.5, as itis customary to provide casing with righthand threads which .consequent-ly are ,unsc'rewed by rotating in lefthanddirjection. Y

Il claim asmy invention: 1. In an adjustable backcombination of: iadapted to be lowered intoacasing; and means for expanding said memberwhen the desired point has been reached. U Y i v Y Y 2. In an adjustablebacking off spear, the combination of: Y i adapted to be lowered into acasing;i and rotary means for expanding said member when the desiredpoint has been` reached.

3. In an adjustable backing ott" spear, the combination of: i anr`expar'1siblemember adapted to be lowered between innei1 and outer pipemembers; gripping teeth arranged on said expansible member;- and meansfor expanding said member when the desired point has been reached. i 4.In an adjustable backing on spear, the combination of: an expansiblemember adapted to be lowered between inner and outer pipe members;grip-ping teeth arranged on said expansible memberj and r'otary meansfor. expanding said member when the desired point has been reached. I

5. In an adjust-able backing off spear, the

ng off spear, the

an expansible niember combination of: an expansible member adapted to belowered between .inner and outerr pipe members, said expansible membercomprising cooperating Y i 'wedge members having gripping teeth on theouter surfaces thereof; and means tor accomplishing a comliirising anouter wedge member having a convex, `toothed face, and an inner wedgemember having a concave, toothed face; and means for accompflishing arelative londitiidinal movement between said wefge members. i'

8. In adjustable backing ont spear arranged fr, lowering between innerand outer pipe members, the combination of: an outer kwedge member; aninner wedge member;

and means for accomplishing a relative longitiidinal movement betweenVsaidv wedge I members.

I y9. In an adjustable backing ofi' spear ai'- ranged for loweringbetween inner and outer pipe members,- Ythe combination of an outerwedge nieinher; an inner wedge member, having .channels formed in thesides thereof; side plates secured to said outer wedge member, said sideplates Vengaging in said channels vfor aligning said wedge members; andmeans for accomplishing a relative lo'ngitudinalk movement between saidwedge members...

i 10. In an adjustable backing oifspea'r are ranged or'lowering betweeninner and cuter vpipe members, the combinationgof an outer wedge member;an inner wedge member; a nut retamed by one ofsaid wedge members; andasha-ft threaded'through said nut and 'being' rotatable butnon-longitudinally movably secured to the other of said rwedge members,a rotation of said shaft causing said nut to move along said shaft andthereby producing a relative movement between Vsaid wedge members.

11. In an adjnstable backing olf spe-ar arranged t'or lwering betweenvinner and outer pipe members, the combination oi" an outer wedgemember;- anv inner wedge member, having channels Vformed in the sidesthereof; 'side p ates secured to said outer wedge'member, said sideplates engaging in said channels in a manner to align said Wedgemembers; a. nut retained by one of said wedge members; and a` shaftthreaded through said nut and being rotatably7 but non-longitudinallymovably secured to the other of said Wedge members, a rotation of saidshaft causing said nut to move along said shaft and thereby producing arelative movement between said Wedge members.

In testimony whereof, have hereunto set 1`0` my hand at Los Angeles,California, this 23rd dayfof OctoberE 1923. Y

MILTON S. DICK. y

